Self-threading sewing machine needle with improved block



Feb. 17, 1953 G. MARTINELLI 2,628,582

SELF-THREADING SEWING MACHINE NEEDLE WITH IMPROVED BLOCK Filed 001;. 29,1951 Guido Martina/Ii INVEN TOR.

.BY ova/mun; FM

Patented Feb. 17 1953 UNITED STATES PATENT OFFICE SELF THREADING SEWINGMACHINE NEEDLE WITH IMPROVED BLOCK 3 Claims.

The present invention relatesito certainnew and useful improvements in:sewing machine needles of the self-threading type and'relates moreparticularly to a novel needle, a novel: block into which it is fitted,andthe improved'endxresult effected through this combination needle andblock.

Summarized briefly, :the over-all concept has to do with a structurallydistinct especially slotted needle, a block into which'the shank of theneedle is fitted :wherein said vlolockihas-a thread guiding 'cam andbeingfurther provided with a complementalguide which encompasses Y thethread and I shunts and properly pilots 1 the same intothe coacting slotmeans" inthe; needle.

Anotherobject of the invention'has to do with a needle which ischaracterized by a shank pointed at one end and provided at said endwith a thread receiving eye, and further provided with a lengthwise slotregistering with and ranging axially 'fromsaid'eye and opening laterallythrough one side of the'intermediate portion of said shank and thusproviding a-thread inlet opening.

Another object of the invention has to do with 'the'stated needlewhereinthe presence of the needle barplock by the usualset screw, said blockhaving guide means "on .one side which takes the form of a loop, onecn'dof the;loop;being fixed and the other end free and flexible andprovided with a socket which constitutes a keeper for the coactingdetent on the flexible portion of the needle.

More importantly, the invention has to do with the combination of ablock and slotted needle with an especially shaped thread retaining eyein like'numerals areemploye'd to designate like parts throughout theviews:

Figure 1 is a view partly in section and partly in elevation of a needlebar, block and'needle combination constructed in accordance with theprinciples or the present invention.

Figure 2 is a perspective view of the needleby itself.

Figure 3 is an enlarged cross-sectionon the lines-3 of Figure 1.

Figure 4 is a fragmentary bottom planview of the block.

Referring now to the drawings and especially to Figure l, the numeral 6denotes a reciprocable needle bar having needle attaching means on itslower end. The means is sometimes referred to as a head, in otherinstances as a needle collar and in others merely as a needle block.Here, it is well to think of'the element in question as a block and thesame is denoted by the numeral 8 and is generally rectangular andprovided with an axial socket 50 provided with a set screw l2, saidsocket'being adapted to accommodate, as usual, the shank portion M ofthe'sewing machine needle I 8. The block is distinct in that one lowercorner portion is relieved, and properly shaped up to provide a threaddirecting cam surface l8. Another improvement has to do with the threadguide means 20. Specifically, this takes the form of a loop ofappropriate size and general shape, which permits the free end of thethread (not shown) to be drawn therethrough so it will be all set tofind its way into theselfthreading needle to be hereinafter particularlydescribed. Said loop has'one curved end portion 22 integrally formed atto the upper portion of the block. The other end portion 26 is flexibleand free-and has a cam surface 28 which -coacts with the cam surface I 8in refining asort of a curvate channel for channeling the thread intothe needle. The terminal of this end portion is provided with a keeperrecess or socket 3|] to be hereinafter described.

Taking up now in detail the construction of the needle best shown inFigure 2 it is clear, as before indicated, that this is characterized bythe usual point 32 having an eye 34 therein. This eye is distinct herebecause it is of general heartshaped configuration with lobe portions36-36 situated on opposite sides of close spaced parallel surfaces 3838defining an end portion of slot means 40. The latter is axially arrangedand opens into the eye by way of the restriction 38-48. This restrictionplus the heart-shaped configuration of the eye prevents the thread fromaccidentally slipping out of place once it is through the slot and inthe eye proper. The slot means is such that it axially divides the shankof the needle into a relatively rigid portion 42 on one side of the slotand a flexible portion or finger 44 on the opposite side of the slot.The stationary part has a curvate surface 46 which is coincident withthe cam surface 18 as best shown in Figure 1. The free end of the fingeris laterally flared as at 48 where it i then properly lined up with theabutment surface 50 (see Figure 4) on the free end portion of the guideloop. In fact there is a fiat abutment at 52 which engages the abutment50 and the former is provided with a detent 54 which is removablysnapped into the keeper socket 30. Thus, the finger portion of theneedle is mechanically joined with the free end portion of the guideloop. This brings all surfaces into requisite companionate relationshipto provide an effective self-threading block and needle assembly.

In operation the free end of the thread is passed through the opening inthe loop means 20. One end of the thread being attached to the usualspool on the head of the sewing machine, the free end is merely pulledthrough and then down against the surfaces 18 and 28 where it is pilotedand channeled into the entrance of the slot, then drawn down in theslot, passed through the constriction mean 3838 and trapped and retainedin an obvious manner in the eye 34 of the needle.

Minor changes in shape, size, materials and rearrangement of parts maybe resorted to in actual practice provided no departure is made from theinvention as claimed.

Having described the invention, claimed as new is:

1. In a self-threading needle construction, in combination, a needle barhaving a block which is flat at one end, said block having an axialsocket therein opening centrally through said flat end for reception ofthe shank of a needle, said needle having a shank with its inner endfitting into said socket and having an eye at its outer end and alengthwise thread delivering slot opening at one end into said eye andopening at its opposite inner end laterally and outwardly through a sideof the intermediate portion of said what is shank remote from said eyeand providing a '1 thread inlet to said slot, that portion of the blockwhich is in alignment with said inlet having a cam surface for directinga contacting thread into said slot for delivering said thread into saideye, and a thread guide situated on that portion of said block havingsaid cam surface and in which the free end of the thread is initiallyand momentarily corralled and piloted toward said cam surface andcooperating inlet, said guide being in the form of a loop and having oneend fixed on said block and the other end free and in close spacedproximity to said flat end, said free end having an outwardly disposedsurface which is coplanar with said fiat end and also having an inwardlypositioned cam surface opposed to said first cam surface and said camsurfaces conjointly functioning to channel the thread into said inlet.

2. In a self-threading needle construction, a needle bar having a block,said block being provided with an axial socket opening at its outer endthrough the corresponding end of said block for reception and retentionof the shank portion of an insertable and removable needle, one sidesurface of said block being relieved and formed into a thread glidingand directing cam surface, said cam surface being located in closeproximity to the outer end of said block and merging into andregistering with the outer open end of said socket, and a guide loopsituated on said one side surface of said block and having one endformed integrally with said one side surface, and the other end free andterminating in close proximity to said cam surface, said free end havinga cam surface opposed to and aligned with said first named cam surfaceand said two cam surfaces defining a gradually narrowing crotch andpiloting channel for a coacting thread.

3. The structure defined in claim 2, and the combination therewith of a,needle having a rigid shank with its inner end fitted into said socketand its outer end projecting axially beyond the socket, the projectingouter end of the shank having eye means at the outer end of the shankand also having lengthwise slot means in communication at its outer endwith said eye means, said slot means opening at its inner end through anintermediate portion of the shank at a point removed from said eye meansand dividing the cooperating portions of the shank into rigid andflexible portions, the free end of said flexible portion terminatingadjacent to and being aligned with and abutting the free end of saidguide loop, the latter free end having a keeper socket and the free endof said flexible portion having a detent fitting removably into saidkeeper socket.

GUIDO MARTIN ELLI.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 110,480 Lloyd Dec. 27, 1870899,381 Bradley Sept. 22, 1908 2,221,419 Autcliif Nov. 12, 1940

